Many residential homes and other buildings are fitted with rain gutters. Rain gutters divert rain water flowing off the roof to a downspout, and thus prevent rain water from dripping off the eaves directly onto the ground. Without gutters, accumulated rain water will fall along a line directly under the eave. This can form an unsightly drip line under the eave, and may damage a lawn or other plantings next to the house. Rain gutters also prevent rain water from falling from the roof onto persons entering or leaving the house.
An age-old problem with rain gutters is blockage due to leaves and other debris. This problem is particularly acute in the fall, when leaves which have fallen on rooftops are washed down by rainfall into the gutters and are carried from there to the mouth of the downspout. Wet leaves easily stick together and can accumulate at the mouth of the downspout, clogging the downspout and causing water to back up into the gutter and overflow.
For such reasons, gutters must periodically be cleaned of debris, particularly in the area near the downspout connection. This usually involves climbing a ladder and using tools and/or pressurized water to remove manually the compacted organic matter. Aside from the inconvenience involved, there is the danger of falling while handling tools or a hose at the top of a ladder, and the possibility that a gutter may be damaged by the weight of the ladder and the person on it. The risk of falling is particularly troubling in the case of multi-story buildings, where a fall could cause serious injury.
One known way to try to reduce clogging in gutters is covering the gutter with a protective screen. Such technique, however, is not entirely effective. Wet leaves which are washed off the roof can stick to the protective screen, blocking the screen openings. When this happens, rain water cannot flow into the gutter, thus defeating the purpose of having a gutter.
Albrecht U.S. Pat. No. 3,638,369 discloses a device for clearing a gutter downspout. An auger device is located in the gutter, above the downspout, such that the auger screw extends a short distance down into the downspout. The shaft of the auger screw is connected to an impeller, located above the gutter, such that when the wind blows, the impeller rotates the screw shaft, and the rotating screw in turn forces downwardly any solid matter with which it is in contact.
Albrecht only works while the wind is blowing. If it is raining, and there is insufficient wind to rotate the screw, water-soaked leaves and other sticky debris may accumulate at the downspout inlet, clogging the downspout inlet. The auger screw, in fact, makes a blockage more likely, both because the screw partially blocks the downspout opening, and because the screw surfaces are substantially perpendicular to the direction of flow, and thus likely to attract the wet, sticky leaves.
If waterlogged organic matter does accumulate around the screw, when the wind again starts to blow it will be harder to start the screw rotating, particularly if it has stopped raining and the matter has partially dried out and hardened. Thus, the auger may become stuck and need to be manually cleaned before it will work again.
In Albrecht, even when the auger is operational, leaves and other debris may clog the downspout at its lower end, because the auger pushes the organic mass downwardly generally intact. The auger may actually exacerbate the tendency to clog, insofar as the screw compacts the organic mass while extruding it through the downspout inlet.
There is a need for a more effective system for keeping gutters clear. There is also a need for such a system which does not require climbing ladders and, preferably, other human intervention.